Processing apparatus for processing a workpiece surface with fluid flow shielding

ABSTRACT

Processing apparatus for processing a workpiece surface in form of an internal coating of cylinder bores which are arranged in a row. The apparatus includes a shield unit which is provided to separate from one another—at least during operation—a part region of the workpiece surface provided for the processing and an adjacently arranged part region of the workpiece surface, whereby the shield unit has at least one blocking nozzle which is provided to generate a fluid flow for separating the at least two part regions, wherein the blocking nozzle is positioned such that the fluid flow flows along the workpiece surface and the blocking nozzle is directed to the part region between two cylinder bores.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. Ser. No. 14/267,155 filed on May 1, 2014 which claims priority under 35 U.S.C. § 119(a) of European Patent Application No. 13166353.6 filed May 3, 2013, the disclosures of which are expressly incorporated by reference herein in their entireties.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The invention relates to a processing apparatus for processing a workpiece surface and to a method.

2. Discussion of Background Information

A processing apparatus for the internal coating of cylinder bores is already known from DE 10 2008 016 040 B3 having a shield unit which is provided to separate a part region of a workpiece surface provided for processing and a part region of the adjacently arranged workpiece surface at least during operation.

SUMMARY OF THE EMBODIMENTS

Embodiments of the invention provide a simple, flexibly usable processing apparatus for processing a workpiece surface as well as a corresponding method. Embodiments are directed to a processing apparatus in accordance with the invention and to a method in accordance with the invention.

The invention starts from a processing apparatus for processing a workpiece surface, in particular for the internal coating of cylinder bores, having a shield unit which is provided to separate a part region of the workpiece surface provided for processing and a part region of the adjacently arranged workpiece surface at least during operation.

It is proposed that the shield unit has at least one blocking nozzle which is provided to generate a fluid flow for separating the at least two part regions. A reliable separation of the two part regions can thereby be achieved without a mask or similar having to be used which has wear or which has to be cleaned at least from time to time. In addition, a mechanical separation can be dispensed with, whereby the shield unit can be used for different workpieces without different shield apparatus having to be kept available. A simple, flexibly usable processing apparatus can thus be provided by a design in accordance with the invention. A “separation during operation” is in this respect in particular to be understood such that only one of the part regions of the workpiece surface is exposed to a processing, whereas the second part region, which would be exposed to a processing without the shield unit, remains unprocessed. A “fluid flow” is in this respect in particular to be understood as a gas flow. A fluid flow for separating the part regions is in particular to be understood as a gas flow which ensures that the adjacently arranged part region, which is not intended for processing, remains free of processing. The processing apparatus is in this respect in particular provided for a contactless processing of the workpiece surface, such as a plasma coating or similar. A separation is in this respect in particular not to be understood as a mechanical separation of the part regions.

It is further proposed that the fluid flow which can be generated by the blocking nozzle is provided at least in part to be directed along the workpiece surface. It can thereby be achieved that the fluid flow flows along the workpiece surface so that the fluid flow can act in an analog manner to a mechanical barrier which is placed onto the workpiece surface. The part regions can thereby be particularly effectively separated from one another. “Directed at least partly along the workpiece surface” is in this respect in particular to be understood such that in operation the fluid flow has a flow direction in at least one part region which is directed at least substantially parallel to a main direction of extent of the workpiece surface. A “flow direction in a part region” is in this respect in particular to be understood as a middle flow direction of a part of the fluid flow. The fluid flow preferably overall has a middle flow direction which is directed along the workpiece surface. “At least substantially parallel” is in this respect in particular to be understood such that the middle flow direction and the workpiece surface have an angle of 180 degrees±90 degrees. A “middle flow direction” is in this respect in particular to be understood as a middle flow direction of the fluid flow directly downstream of the blocking nozzle in a non-disturbed state.

The at least one blocking nozzle is preferably configured as a compressed air nozzle. The shield unit can thereby be particularly easily supplied with a fluid. Generally, however, other fluids, in particular other gases, can also be used for operating the blocking nozzle.

The blocking nozzle is particularly advantageously provided to generate a flat jet. A particularly advantageous shielding can thereby be achieved. The blocking nozzle can, however, generally also be provided for generating a round jet or another jet shape. A “flat jet” or a “round jet” are in this respect in particular to be understood as a shape of the flow fluid which is provided to separate the part regions from one another independently of a mechanical separation.

The blocking nozzle can alternatively also be provided to generate a compressed air cushion. A good shielding can likewise thereby be achieved. A “compressed air cushion” is in this respect in particular to be understood, in contrast to a flat jet or a round jet, as a shape of the fluid flow which is provided to generate the compressed air cushion in a region upstream of the blocking nozzle, whereby the blocking nozzle can provide a mechanical separation in addition to the separation by the fluid jet.

It is further proposed that the processing apparatus has a torch for processing the workpiece surface. By using a shield apparatus having a blocking nozzle in conjunction with a torch, a particularly simple, inexpensive processing apparatus can be provided for refining workpiece surfaces. A “torch” should in this respect in particular be understood as a unit for refining a workpiece surface under the effect of a temperature such as a unit for plasma coating or similar.

The fluid flow which can be generated by the at least one blocking nozzle is preferably provided for deflecting a torch jet of the torch. The torch jet of the torch can thereby be simply deflected by the part region which is arrange adjacent to the part region provided for processing, whereby the part regions can be simply separated from one another by a torch with respect to a processing.

The blocking nozzle and the torch are particularly preferably arranged at an angle toward one another between 80 degrees and 150 degrees. The torch jet can thereby be deflected with high reliability. An “angle between the blocking nozzle and the torch” is in this respect in particular to be understood as an angle between a main expulsion direction of the blocking nozzle and a radiation direction of the torch. A “radiation direction” is in this respect in particular to be understood as a middle flow direction of the torch jet directly downstream of the torch.

Alternatively, the blocking nozzle and the torch can, however, also be arranged at an angle toward one another of approximately 180 degrees. Such a design is in particular advantageous when the blocking nozzle is provided to generate a compressed air cushion. “Approximately” should in this respect in particular be understood as a deviation of at most 10 degrees, advantageously of at most 5 degrees.

It is additionally proposed that the at least one blocking nozzle can be positioned relative to the torch. The blocking nozzle can thereby be positioned independently of the torch, whereby cylinder housings of different constructions can be processed.

It is further proposed that the processing apparatus has a second blocking nozzle which is provided to be arranged opposite the first blocking nozzle with respect to the torch. A two-sided shielding can thereby be achieved, whereby a part region, which is provided for processing, can be delineated from a plurality of part regions which are arranged in an adjacent manner. The blocking nozzles can preferably be positioned independently of one another.

In addition, it is advantageous if the processing apparatus has a support unit for the torch which has a support axis which is directed at least substantially perpendicular to a main expulsion direction of the at least one blocking nozzle. In particular inner walls of cylinder bores can thereby be processed without the inner walls of adjacent cylinder bores simultaneously being contaminated.

It is additionally proposed that the processing apparatus has a control unit for controlling the at least one blocking nozzle which is provided to activate or deactivate the blocking nozzle in dependence on an alignment and/or position of the torch. A demand-actuated activation of the blocking jet can thereby be achieved, whereby a consumption of fluid for operating the shield unit can be reduced. “In dependence on an alignment and/or a position of the torch” is in this respect in particular to be understood such that the control unit is provided to determine an angle-dependent alignment of the torch with respect to the rotational axis of the torch and/or an axial position of the torch along a direction of longitudinal extent of the cylinder bore and to switch on and/or switch off the blocking nozzle in dependence on the angle-dependent alignment and/or on the axial position of the torch.

In accordance with the invention, a method of processing a workpiece surface, in particular for an internal coating of cylinder cores, is moreover proposed, wherein a part region of the workpiece surface provided for the processing and an adjacently arranged part region of the workpiece surface are separated from one another at least during operation, wherein a fluid flow for separating the at least two part regions is generated by at least one blocking nozzle, whereby a workpiece surface can be processed particularly simply and the method can be used flexibly.

Further advantages result from the following description of the Figures. Two embodiments of the invention are shown in the Figures. The Figures, the description of the Figures and the claims contain a number of features in combination. The skilled person will also expediently consider the features individually and combine them to further sensible combinations.

Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of exemplary embodiments of the present invention, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein:

FIG. 1 shows a schematic representation of a processing device having a shield unit;

FIG. 2 shows a perspective representation of a workpiece configured as a crankshaft housing with a blocking nozzle;

FIG. 3 shows a further embodiment of a processing apparatus with a shield unit in a side view; and

FIG. 4 shows the processing apparatus of FIG. 3 in a perspective representation.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show structural details of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied in practice.

FIGS. 1 and 2 show a processing apparatus for processing a workpiece 28 a. The processing apparatus is preferably used for postprocessing cylinder bores 11 a, 12 a, 13 a or combustion chambers in a cylinder housing, in particular in a crankshaft housing of internal combustion engines for motor vehicles. The processing apparatus is in particular provided for the internal coating of cylinder bores 11 a, 12 a, 13 a or of combustion chambers. For example, inner walls of the cylinder bores 11 a, 12 a, 13 a can be provided with a coating or a surface structure of the inner wall can be changed by the processing apparatus. The processing apparatus can, however, generally also be used for processing other hollow spaces.

The cylinder housings such as can be processed by the processing apparatus typically have a plurality of cylinder bores 11 a, 12 a, 13 a which are arranged in a row. The processing apparatus is provided to process the cylinder bores 11 a, 12 a, 13 a successively after one another, i.e. always only one of the cylinder bores 11 a, 12 a, 13 a is processed. For processing the workpiece 28 a, the processing apparatus comprises a torch 22 a which is provided to be directed toward a workpiece surface 10 a of the workpiece 28 a. The torch 22 a comprises a nozzle which is provided to generate a torch beam 23 a which is directed toward the inner wall of the corresponding cylinder bore 11 a, 12 a, 13 a in operation. The torch 22 a has a radiation direction 29 a which is aligned in operation perpendicular to a longitudinal direction of extent of the corresponding cylinder bore 11 a, 12 a, 13 a. In operation, the torch 22 a is introduced into the cylinder bore 11 a, 12 a, 13 a to be processed along the longitudinal direction of extent and is directed toward the inner wall of the cylinder bore 11 a, 12 a, 13 a. The inner wall of the corresponding cylinder bore 11 a, 12 a, 13 a in such a case forms a part region 15 a of the workpiece surface 10 a of the workpiece 28 a which is provided for a processing by the torch 22 a.

Due to the design, the torch jet 23 a generated by the torch 22 a has an expanded region which in particular has the result on the processing of marginal regions of the cylinder bores 11 a, 12 a, 13 a that the torch beam 23 a can also be incident on part regions 16 a, 17 a of the workpiece surface 10 a which are arranged adjacent to the part region 15 a provided for the processing. To separate the part region 15 a provided for processing and the adjacent part regions 16 a, 17 a from one another during operation, the processing apparatus has a shield unit 14 a. The shield unit 14 a is in this respect in particular provided to shield the part regions 16 a, 17 a, which are arranged adjacent to the part region 15 a provided for processing, from the torch 22 a.

To shield the part region 16 a, the shield unit 14 a has a blocking nozzle 18 a which is provided to generate a fluid flow 20 a for separating the part regions 15 a, 16 a. The blocking nozzle 18 a is in this respect in particular provided to generate a fluid flow 20 a which is directed along the workpiece surface 10 a in a part region 30 a which is arranged spatially between the two part regions 15 a, 16 a to be separated (cf. FIG. 2). The fluid flow 20 a generated by the blocking nozzle 18 a has an expanded portion by which the fluid flow 20 a is at least partly also directed toward the workpiece surface 10 a. The fluid opening 20 a thus forms a barrier which adapts to the workpiece surface 10 a. The part regions 15 a, 16 a of the workpiece surface 10 a are separated from one another in a technical processing aspect by the fluid flow 20 a.

The blocking nozzle 18 a is configured as a compressed air nozzle. Compressed air is supplied to the blocking nozzle 18 a, for example via a compressor, as a fluid for generating the fluid flow 20 a. Alternatively, the blocking nozzle 18 a can, however, also be operated using other operating media by which a fluid jet can be generated such as using nitrogen or using other gases. The blocking nozzle 18 a is preferably provided to generate a flat jet. The flat jet forms the technical flow barrier by which the part regions 15 a, 16 a of the workpiece surface 10 a are separated from one another in operation. The blocking nozzle 18 a can, however, generally also have a different design.

The fluid flow 20 a which can be generated by the blocking nozzle 18 a is provided to deflect the torch jet 23 a of the torch 22 a. The fluid flow 20 a has a strength in operation which is at least substantially impenetrable for the torch jet 23 a. The fluid flow 20 a and the torch jet 23 a are aligned at an angle 24 a toward one another unequal to 180 degrees. The angle 24 a at which the torch 22 a and the blocking nozzle 18 a are arranged toward one another ideally lies between 90 degrees and 135 degrees, but can generally also be smaller than 90 degrees or greater than 135 degrees. In the embodiment shown, the angle amounts to 90 degrees. The blocking nozzle 18 a in this respect has a main expulsion direction 27 a which includes the angle 24 a of approximately 90 degrees with the radiation direction 29 a of the torch 22 a.

The blocking nozzle 18 a can be positioned relative to the torch 22 a. In operation, the blocking nozzle 18 a is positioned such that the fluid flow 20 a flows along the workpiece surface 10 a. With a cylinder housing having a plurality of cylinder bores 11 a, 12 a, 13 a arranged in a row, the blocking nozzle 18 a is directed to the part region 30 a between the two cylinder bores 11 a, 12 a. The fluid flow 20 a thus separates the two cylinder bores 11 a, 12 a from one another in a technical processing aspect. The fluid flow 20 a has the effect that the torch jet 23 a of the torch 22 a is only incident on the inner wall of the one cylinder bore 11 a and is deflected before it is incident onto the inner wall of the other cylinder bore 12 a.

In order also to separate the inner wall of the third cylinder bore 13 a from the inner wall of the cylinder bore 11 a which is provided for the processing, the shield unit 14 a comprises a second blocking nozzle 19 a. The further blocking nozzle 19 a is configured in an analog manner to the first blocking nozzle 18 a. The blocking nozzle 19 a is likewise provided to generate a fluid flow 21 a which is directed along the workpiece surface 10 a of the workpiece 28 a configured as a cylinder housing. The second blocking nozzle 19 a is arrange opposite the first blocking nozzle 18 a with respect to the torch 22 a.

The two blocking nozzles 18 a, 19 a are aligned in parallel with one another. In operation, the fluid flow 20 a generated by the first blocking nozzle 18 a and the fluid flow 21 a generated by the second blocking nozzle 19 a flow substantially parallel to one another. A spacing between the two fluid flows 20 a, 21 a approximately corresponds to a diameter which the cylinder bore 11 a has which is provided for the processing. The torch 22 a is arranged in operation between the two fluid flows 20 a, 21 a, which are generated by the blocking nozzles 18 a, 19 a.

To guide the torch 22 a, the processing apparatus comprises a support unit 25 a which rotatably supports the torch 22 a. The support unit 25 a has a support axis 26 a about which the torch 22 a rotates at a defined rotational speed in operation. The total inner wall of the corresponding cylinder bore 11 a is processed by the rotation of the torch 22 a. The support axis 26 a for the torch 22 a is oriented perpendicular to the main expulsion directions 27 a, 31 a of the blocking nozzles 18 a, 19 a and in parallel with the longitudinal extent of the cylinder bore 11 a.

The blocking nozzles 18 a, 19 a of the shield unit 14 a each have a valve by which the blocking nozzles 18 a, 19 a can be individually controlled. The processing apparatus has a control unit, not shown in any more detail, to control the blocking nozzles 18 a, 19 a.

The control unit is provided to control the blocking nozzles 18 a, 19 a in dependence on a position and an alignment of the torch 22 a. The control unit only activates the blocking nozzles 18 a, 19 a when the torch jet 23 a can impact the adjacently arranged part regions 16 a, 17 a and deactivates the blocking nozzles 18 a, 19 when the torch jet 23 a is only incident onto the part region 15 a of the workpiece surface 10 a provided for the processing.

The axial position of the torch 22 a along the longitudinal direction of extent of the cylinder bore 11 a forms a primary control value for the blocking nozzle 18 a, 19 a. In particular when the torch 22 a is immersed deep into the cylinder bore 11 a, the torch jet 23 a is completely incident onto the inner wall of the cylinder bore 11 a so that only the part region 15 a provided for the processing is exposed to the torch jet 23 a. A value for axial positions at which the control unit deactivates the blocking nozzles 18 a, 19 a is stored in the control unit.

The angle-dependent alignment of the torch 22 a with respect to the support axis 26 b of the support unit 25 a forms a further control value for the blocking nozzles 18 a, 19 a. The control unit which is simultaneously provided for controlling a drive for the torch 22 a comprises a rotational speed sensor which is provided to determine a rotational speed of the torch 22 a. The rotational speed sensor can, however, also generally be dispensed with when a motor having a fixed rotational speed such as a stepper motor is used for the drive. The control unit only activates the corresponding blocking nozzle 18 a, 19 a when the radiation direction 29 a of the torch 22 a and the main expulsion direction 27 a, 31 a of the corresponding blocking nozzle 18 a, 19 a intersect, i.e. when the torch jet 23 a can be deflected by the fluid flow 20 a, 21 a of the corresponding blocking nozzle 18 a, 19 a. The fluid flow 20 a, 21 a of the corresponding blocking nozzle 18 a, 19 a thereby has a timing which the control unit adapts to the rotational speed of the torch 22 a. The timing of the shut-of nozzles 18 a, 19 a can, however, generally also be dispensed with.

A further embodiment of the invention is shown in FIGS. 3 and 4. The following descriptions are substantially restricted to the differences between the embodiments, with reference being able to be made to the description of the embodiment of FIGS. 1 and 2 with respect to components, features and functions which remain the same. To distinguish the embodiments, the letter a in the reference numerals of the embodiment in FIGS. 1 and 2 is replaced with the letter b in the reference numerals of the embodiment of FIGS. 3 and 4. Reference can generally also be made to the drawings and/or the description of the embodiment of FIGS. 1 and 2 with respect to components of the same name, in particular with respect to components with the same reference numerals.

FIGS. 3 and 4 show a further processing apparatus for processing a workpiece surface 10 b, in particular for an internal coating of cylinder bores 11 b, 12 b, 13 b in a crankshaft housing of an internal combustion engine having a plurality of cylinders arranged in a row. For processing the workpiece 28 a, the processing apparatus comprises a torch 22 b which is provided to be directed toward the workpiece surface 10 b of the workpiece 28 b. The torch 22 b, which is configured analog to the preceding embodiment, comprises a nozzle which is provided to generate a torch jet 23 b which is directed in operation toward an inner wall of the corresponding cylinder bore 11 b, 12 b, 13 b. In addition, the processing apparatus comprises a support unit 25 b for the torch 22 b which is provided to rotate the torch 22 b about a support axis 26 to process the total inner wall of the cylinder bore 11 b. Analogously to the preceding embodiment, the inner wall of the cylinder bore 11 b toward which the torch 22 b is directed forms a part region 15 b of the workpiece surface 10 b provided for the processing, whereas the inner walls of the adjacently arranged cylinder bores 12 b, 13 b form part regions of the workpiece surface 10 b which are not shown in any more detail and which are not provided for processing.

The processing apparatus comprises a shield unit 14 b which is provided to separate from one another—during operation—the part region 15 b of the workpiece surface 10 b provided for the processing and adjacently arranged part regions of the workpiece surface 10 b. The shield unit 14 b has two blocking nozzles 18 b, 19 b which are provided to generate a fluid flow 20 b, 21 b for separating the part region 15 b of the cylinder bore 11 b which is provided for the processing and the part regions not shown in any more detail of the adjacently arranged cylinder bores 12 b, 13 b which are not provided for the simultaneous processing. The blocking nozzles 18 b, 19 b are provided to generate a fluid flow 20 b, 21 b which is aligned partly along the workpiece surface 10 b. The blocking nozzles 18 b, 19 b are configured as compressed air nozzles.

Unlike the preceding embodiment, the blocking nozzles 18 b, 19 b are configured as multichannel nozzles which have a plurality of outflow openings 32 b. The blocking nozzles 18 b, 19 b thereby generate a compressed air cushion which deflects the torch jet 23 b of the torch 22 b. The two blocking nozzles 18 b, 19 a are of identical design.

The blocking nozzle 18 b, the same also applies correspondingly to the blocking nozzle 19 b, comprises a base body 33 b into which the outflow openings 32 b are introduced. The base body 33 has a main direction of extent 34 b which is directed perpendicular to the support axis 26 b of the torch 22 b and is directed perpendicular to an irradiation direction 29 b of the torch 22 b. The outflow openings 32 b are introduced in the form of forms which are introduced into the base body 33 b. The base body 33 has a round cross-section in the embodiment shown. It is of tubular design. A different design of the base body 33 b is, however, generally also conceivable.

The outflow openings 32 b introduced into the base body 33 b are distributed along the main direction of extent 34 b and along a peripheral direction over the base body 33 b. The base body has a length along the main direction of extent 34 b which is at least equally as large as a diameter which the cylinder bores 11 b, 12 b, 13 b to be processed have. The outflow openings 32 b are arranged in the form of a matrix arrangement which has a longitudinal extent along the main direction of extent 34 b which is likewise at least equally as large as the diameter of the cylinder bores 11 b, 12 b to be processed. A plurality of rows of outflow openings 32 b are arranged above one another perpendicular to the main direction of extent 34 b. The matrix arrangement can in this respect have different transverse extents perpendicular to the main direction of extent 34 b. The transverse extent in particular depends on the torch 22 b used and/or on the cross-section of the base body 33 b. If the base body 33 b, as shown, has a round cross-section, the matrix arrangement can have a different transverse extent, as if the base body 33 b had a rectangular cross-section.

The blocking nozzle 18 b has a main expulsion direction 27 b which is defined by the outflow openings 32 b and which is aligned perpendicular to the support axis 26 b of the torch 22 b. The fluid flow 20 b of the blocking nozzle 18 b thereby has a mean flow direction which is directed parallel to the main expulsion direction 27 b. The fluid flow 20 b has an expansion of at least 90 degrees about the main expulsion direction 27 b due to the transverse extent in the matrix arrangements of the outflow openings 32 b of the base body 33 b. In the embodiment shown, the expansion amounts to approximately 150 degrees.

The shield nozzle 18 b is arranged between the cylinder bores 11 b, 12 b to shield the part regions of the workpiece surface 10 b not provided for the processing. Due to the great expansion, some of the fluid flow 20 b which can be generated by the blocking nozzle 18 b is directed toward a part region 30 b of the workpiece surface 10 b. A further portion of the fluid flow 29 b is directed along the workpiece surface 10 b in the part region 30 b. In addition, a portion of the fluid flow 20 b is directed away from the workpiece surface 10 b. The fluid flow 20 b thereby forms the compressed air cushion which deflects the torch jet 23 b of the torch 22 b in operation. The blocking nozzle 18 b and the torch 22 b are in this respect arranged at an angle 24 b of 180 degrees with respect to one another, i.e. the main expulsion direction 27 b of the blocking nozzle 18 b and an irradiation direction 29 b of the torch 22 b are arranged antiparallel to one another.

A design of the blocking nozzles 18 b, 19 b as multichannel nozzles having an expansion of less than 90 degrees is generally also conceivable. The base body 33 b can, for example, have a rectangular cross-section having a surface which faces the torch 22 b and in which all outflow openings 32 b are introduced. The outflow openings 32 b in such a design are each aligned parallel to one another and generate a compressed air cushion which deflects the torch jet 23 b in front of the surface facing the torch 2 b.

It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to an exemplary embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims. 

What is claimed:
 1. A processing apparatus for processing a workpiece surface in form of an internal coating of cylinder bores which are arranged in a row, the apparatus including a shield unit which is provided to separate from one another—at least during operation—a part region of the workpiece surface provided for the processing and an adjacently arranged part region of the workpiece surface, whereby the shield unit has at least one blocking nozzle which is provided to generate a fluid flow for separating the at least two part regions wherein the blocking nozzle is positioned such that the fluid flow flows along the workpiece surface and the blocking nozzle is directed to the part region between two cylinder bores.
 2. A processing apparatus in accordance with claim 1, wherein the at least one blocking nozzle is configured as a compressed air nozzle.
 3. A processing apparatus in accordance with claim 1, wherein the blocking nozzle is provided to generate a flat jet.
 4. A processing apparatus in accordance with claim 1, further comprising a torch for processing the workpiece surface.
 5. A processing apparatus in accordance with claim 4, wherein the fluid flow which can be generated by way of the at least one blocking nozzle is provided for deflecting a torch jet of the torch.
 6. A processing apparatus in accordance with claim 4, wherein the blocking nozzle and the torch are arranged at angle toward one another between 80 degrees and 150 degrees.
 7. A processing apparatus at least in accordance with claim 4, wherein the blocking nozzle and the torch are arranged at angle toward one another of approximately 180 degrees.
 8. A processing apparatus at least in accordance with claim 4, wherein the at least one blocking nozzle can be positioned relative to the torch.
 9. A processing apparatus at least in accordance with claim 4, further comprising a second blocking nozzle is provided to be arranged opposite the blocking nozzle with respect to the torch.
 10. A processing apparatus at least in accordance with claim 4, wherein a support unit for the torch is utilized which has a support axis which is directed at least substantially perpendicular to a main expulsion direction of the at least one blocking nozzle.
 11. A processing apparatus in accordance with claim 8, further comprising a control unit for controlling the at least one blocking nozzle and which is provided to activate and/or to deactivate the blocking nozzle in dependence on an alignment and/or a position of the torch.
 12. A method of processing a workpiece surface in form of an internal coating of cylinder bores which are arranged in a row, wherein a part region of the workpiece surface provided for the processing and an adjacently arranged part region of the workpiece surface are separated from one another at least during operation, whereby a fluid flow for separating the at least two part regions is generated by at least one blocking nozzle wherein the blocking nozzle is positioned such that the fluid flow flows along the workpiece surface and the blocking nozzle is directed to the part region between two cylinder bores. 